Lionel sent out an email in response to this issue with an easy fix! Please see below:
We are aware that the latest run of Fastrack O72 left hand switches are having trouble with the anti-derailing feature and this may go across all recently released LH switches.
The known issue is that the anti-derailing feature is wired backwards (see attached video for a demo), and this is an easy fix. 2 wires are in the wrong position and just need to be unplugged and swapped, no soldering needed.
Backwards Anti-Derail Wiring Fix
To fix Fastrack switches that have the anti-derailing feature operating opposite of what they are supposed to do is a simple fix.
Simply locate the blue and green wires that are attached to the split rails, pull the wires off the lugs and swap them as seen in the photos below.
Circled here are the incorrectly attached wires, blue to thru (straight) and green to out (curve)
Circled here is the correct wiring, green to thru (straight) and blue to out (curve)
If you have any questions, please contact the Lionel Service Team at email@example.com.